There are conventional collision warning devices, which assist the driver in driving the motor vehicle to contribute toward reducing the risk of accidents. Such collision warning devices are part of a driver assistance system, for example, including a positioning system in the form of an angle-resolving radar sensor, for example, with which distances, relative velocities and azimuths of objects located in front of the vehicle may be measured. On the basis of these data and the dynamic data of the vehicle, the collision warning device then detects that a collision is imminent, for example, and may calculate in particular a time after which the collision would occur if the dynamic status of the vehicle were not altered. If this time is below a certain threshold value, a warning signal is output and then converted to an acoustic warning signal for the driver, for example, or an autonomous emergency braking is triggered to prevent the collision or at least reduce the consequences of same.
German Patent Application No. DE 10 2007 024 391 A1 describes one such collision warning device, which also includes a warning function for an imminent collision with a guide rail at the edge of the lane.